There are a significant number of display devices having a baseball theme of some kind.
U.S. Pat. No. 5,190,829, to Nybye, discloses a wooden baseball bat having a section that is cut away, carved into an ornamental arrangement, and then rejoined to the baseball bat. Similarly, U.S. Pat. Nos. 5,890,308 and 6,009,653, to Harrington, both show display devices designed to appear similar to a baseball bat, but are used as supports for displaying graphic materials. The devices shown in the two Harrington patents are not revised baseball bats.
U.S. Design Pat. Nos. D436,134 (to Aguamo Jr.); D397,885 (to Reed); and D363,184 (to Elhagy) depict display cases having a baseball theme. They variously are for the purpose of displaying baseballs, bats, or cards.
U.S. Pat. No. 5,678,698, to Cabral, shows a baseball bat rack for baseball hats and related articles. It is a display device used for hats, gloves, and the like. It is made from a baseball bat mounted on its end in a base. The display includes a number of pegs that are extendable through the bat's body, but, in any event, are used for hanging the baseball paraphernalia.
None of the cited documents show a display device of the type described and claimed here.